1. Field of the Invention
The present invention relates to a navigation apparatus for guiding a vehicle to a destination, and more particularly, to a navigation apparatus capable of providing guidance such that when the vehicle is traveling toward the destination or a parking lot near the destination in accordance with the guidance, if traffic congestion occurs in an area near the destination, a more suitable parking lot other than the parking lot originally planned to be used is selected and guidance to the selected parking lot is provided or a point suitable for a passenger to get off the vehicle and walk to the destination is selected and guidance to the selected point is provided.
2. Description of the Related Art
A navigation apparatus includes a map/information storage medium such as a CD-ROM, a DVD-ROM, or a hard disk on which map data used to display a map, place name data indicating place names displayed on the map, and information data used to search for facilities or the like are stored. The navigation apparatus also includes a data input/output device for reading or writing data from or onto the map/information storage medium, a display for displaying a map and other information, a vehicle position detector for detecting the current vehicle position and traveling direction in cooperation with a GPS receiver or a self-contained navigation unit such as a distance sensor or a gyroscope. Map data including data indicating the current position of a vehicle is read from the map/information storage medium, and, in accordance with the read map data, a map image of an area in which the vehicle is currently located is displayed on the screen of the display and a mark indicating the position of the vehicle is displayed in a superimposed fashion on the screen of the display. As the vehicle moves, the map image displayed on the screen is scrolled or the mark indicating that the vehicle position has moved while maintaining the map image unmoved so that a user can easily recognize the current position of the vehicle.
The navigation apparatus has the capability of providing route guidance that allows a user to get to a desired destination simply by driving along a route guided by the navigation apparatus. More specifically, suitable routes from a start point to a specified destination are automatically searched for using the map information from numerous possible routes, taking into account the distance, the driving time, the fee, and other factors, and the detected routes are displayed. If a user selects a route from those detected routes, the selected route is stored in a memory as a navigation route. When the vehicle is moving, the route along which to guide the vehicle is displayed on the map image by a bold line with a color different from the color of the other roads. When the vehicle has come to a point within a predetermined range from an intersection at which to make a right or left turn according to the route, an intersection image is displayed in an enlarged fashion, and an arrow indicating the direction of a turn is displayed, or voice information is provided to indicate the direction of the turn.
When the vehicle is moving toward the destination in accordance with route guidance provided by the navigation apparatus, if traffic congestion is detected in an area, for example, near a station specified as the destination or if traffic congestion is detected along the route to the destination, the navigation apparatus immediately searches for a detour route to the destination and displays the detected detour route. If the user selects to drive along the detour route, the navigation apparatus provides route guidance along the detour route. An example of a technique of presenting a detour route as an alternative route when traffic congestion is detected may be found in a patent filed by the present applicant and published as Japanese Unexamined Patent Application Publication No. 08-106597.
In the conventional navigation apparatus, as described above, when traffic congestion occurs on a navigation route, a detour route to avoid the traffic congestion is searched for, and navigation guidance to a destination is provided along the detected detour route. However, for example, when a department store is specified as a destination facility, in an area close to the department store, there may be plural parking lots for dedicated or semi-dedicated use by visitors to the department store. Such a situation presents the possibility that when traffic congestion occurs in an area near the destination facility, use of a parking lot farther from the destination facility allows earlier arrival at the department store specified as the destination facility than driving along a detour route to a parking lot closer to the destination facility, although a longer walking time from the parking lot to the destination facility is needed.
Furthermore, when a passenger other than a driver of a vehicle wants to arrive at a destination facility such as a department store, there is a possibility that getting out of the vehicle at a point before the destination facility and walking therefrom to the destination facility allows earlier arrival than further driving through a congested route to the destination. In some cases, a faster way to reach the department store is to get off the vehicle near a station, get on a train at that station and travel by train to a station close to the department store, and subsequently walk from that station to the department store. Thus, it is very useful to provide information about such a route, including a walking route or a train route. However, the conventional navigation apparatus does not have such a capability.
On the other hand, in a case in which a station is set as a destination to which to take a passenger by vehicle, if traffic congestion occurs in an area near the station, the conventional navigation apparatus simply searches for a detour route to avoid the traffic congestion and presents a detected detour route to a user. However, in such a situation, there is a possibility that the passenger can arrive at the station earlier if he/she gets off the vehicle at a proper point and walks therefrom to the station, rather than traveling further along the detour route by vehicle. For example, in a case in which a passenger is taken by vehicle to a destination facility at which the passenger is going to take an entrance examination or the like, it is very important for the passenger to arrive at the destination by a specified time. In such a case, rather long walking is allowed if walking results in earlier arrival.
In such a case, there is a possibility that the passenger can arrive at the final destination if the passenger gets off the vehicle, not at an originally planned station nearby an area which has traffic congestion, but at another station, although the train route may become longer. However, the conventional navigation apparatus cannot provide such guidance information.